1. Field of the Invention
This invention relates generally to disposable syringes and, in particular, to a release mechanism for a single-use, automatic injection syringe.
2. Description of the Prior Art
Disposable, one time use syringes are known and used in a variety of applications. For example, U.S. Pat. No. 3,114,370 issued to Kayler on Dec. 17, 1963 discloses a syringe designed for hypodermic injection of a liquid medicament into livestock. A barrel chamber is charged with a liquid medicament by withdrawing a plunger to its outer limit. The plunger is latched at its outer limit by a pair of latch dogs that are pivotally mounted and held in place by V-shaped spring means. The latch dogs are unseated from the plunger channel by the action of a pair of rods having sloped caming surfaces acting against the dogs.
An alternate single-use device is disclosed in U.S. Pat. No. 4,237,876 issued to Rumph et al. on Dec. 9, 1980. Rumph shows an anti-rape device designed to contain a rape-deterring fluid and to be worn within a human vagina. A ram is biased in a ready-for-use position by a detent maintained within a groove in the ram until the device is actuated.
Numerous other syringe type devices for numerous other applications are known. For example, men who have hardening of the arteries often have difficulty achieving an erection. This difficulty can be alleviated by administering an artery-dilating medication such as prostaglandin E.sub.1 in the corporacavernosum of the penis to increase blood flow to the penis. The delicate nature of such a situation does, however, require a mechanism that is capable of administering the medication safely, conveniently and with a minimal risk of failure.
Accordingly, there is a need for a syringe type device with a fail-safe release mechanism for administering medication in the area of the shaft of the penis as well as in other areas.